KIM JAE-HWAN/AFP/Getty Images(WASHINGTON) -- Kenneth Bae, the American citizen detained in North Korea, has been moved from a hospital to a labor camp, the U.S. State Department told Bae’s family Friday.

“We are concerned about his health and want him home soon,” said Bae’s sister, Terri Chung.

This latest development has the State Department “deeply concerned,” according to spokesperson Jen Psaki.

“We also remain gravely concerned about Mr. Bae’s health, and we continue to urge DPRK authorities to grant Mr. Bae special amnesty and immediate release on humanitarian grounds,” Psaki said in a statement provided to ABC News.

The North Koreans accuse Bae, a 45-year-old American missionary, of "hostile acts" and attempting to foment a coup.